She said the device was strapped to three propane tanks or small fire extinguishers.

Drennan said authorities will now determine what the capacity of the explosive device could have been if it had exploded.

The canisters will also be tested for fingerprints and other forensic evidence after the explosive device is detached and detonated.

The SkyTrain tracks between Scott Road and Gateway stations were shut down for approximately three hours as police investigated. By 5 p.m. local time, authorities had removed the device and re-opened the line.